Very cool. Are you interested in making different sets of skins for the chess pieces? I built a product called Asset Layer which makes it easy to enable UCG submissions for stuff that like if you are interested in adding it but dont want to design those skins yourself. The product also does all of the player management for who owns what items and enables storefronts and player-to-player marketplaces also.
If that sounds interesting for this game or others you're working on I'd love to show you a quick demo!
Here is a video showing the features available via our Unity integration